What is Receiver Desensitisation?
Receiver desensitization occurs when an undesired signal from a nearby “off-frequency” transmitter is sufficiently close to a receiver’s operating frequency. Â The signal may get through the RF selectivity of the receiver. Â If this undesired signal is of sufficient amplitude, the performance of the receiver is degraded at its operating frequency. Â The gain of the receiver is reduced, thereby reducing the performance of the receiver.
This is not attributable to any specific make or model of radio equipment.
On a typical truck shovel circuit radios operate through a repeater to enable emergency calls & site wide traffic to be heard. Subsequently radios have different transmit & receive frequencies & when a truck transmits in close proximity to another truck it can cause receiver desensitisation causing degradation of the received signal in the adjacent vehicle/s.
Methods to mitigate or rectify this problem include:
- Increasing signal levels in the area by using mobile (trailer) repeaters to supplement coverage from the main repeater towers
- Decrease mobile transmitter power levels
- Operate on a simplex frequency (a procedure to monitor the site wide channel such as a second radio in the shovel to inform the circuit of emergencies would need to be implemented.